For those who upgraded 1.0.x to 1.1.
If you have already done any of Helix transformations during 1.0.x gaming, you still cannot gain its bonuses after upgrading to 1.1. on these soldiers.
To make them available, open your savegame file with Notepad++ and find there string of your soldier, who was transformed to Helix. Then find the string previousTransformations:, delete the string STR_HELIX_KNIGHT: 1 (or PSION) and save the file.
After loading the game Helix transformation will be available again on this soldier with correctly displayed bonuses.